With every dmso solution that you create yourself you want to start with something like a 50% DMSO part(but 99,9% quality) and 50% water and test it first on your arm.
When first mixing a solution dmso +water it will get hot. Wait until that reaction goes down or it will burn skin.
Also only use glass and be clean of any stuff/chemicals that the dmso could transport into your body through the skin.
Then you might do something like 70% dmso, some water to get the heat out of the reaction and then add 30% iodine or whatever you like(I like ascorbic acid - vit.c)